Application Ser. No. 07/804,143 relates to a method utilising non-reactive fillers in an aqueous alkali metal silicate-based curable sealant composition for sealing mine stoppings.
It has now been found that sealant compositions of the type described in Application Ser. No. 07/804,143 may also be used advantageously to seal unstable rock strata. While ready-to-use sealants are known for such general purpose, they are limited by their inability to set in areas of high humidity, or wet conditions where drying cannot take place.
It is known that in underground excavations such as coal mines, seasonal changes in moisture content and air movement can have deleterious effects on the surrounding strata. As a result fragile shale will continuously flake off from the roof and rib, presenting personal hazard in the underground passageways as well as impeding movement due to accumulated debris. Such a condition can progress to the point where major rebolting is necessary to prevent roof collapse.
Additionally as the roof degrades the irregular surface increases resistance to air flow and therefore increases cost of ventilation.
Accordingly elimination of these problems is essential for safe working in the mine and to enable the maintenance of a proper atmosphere affording the least hostile working conditions for miners or workers.
The current method utilized to alleviate this problem involves the use of expensive wire mesh and sprayed concrete.